This invention relates to thermal identification, and more particularly, to a thermal image identification marker utilizing infrared (IR) energy.
The inability of reconnaissance to determine friend or foe in low light or total darkness is a major failing in battlefield and law enforcement operations. The worst effect is that fratricide (the inadvertent killing of friendly forces by other friendly forces) occurs, and at best is a waste of time and resources attempting to confirm identification. Accurate intelligence allows deployment effort to be maximized and focused.
Present marking and identification systems are limited to either Near IR range (1010 nano meters or less) beacons for use with night vision glasses or thermal panel identification marking equipment. Present thermal panel identification marking equipment is passive and only provides identification by temperature or emissivity differences between adjacent areas and the marking equipment. Passive marking equipment is easily masked by surrounding operations, and is difficult to differentiate from adjacent targets.
There is a need to provide a thermal image, which can change state rapidly so as to provide a clear signal in the heat transmission of the spectrum, normally within the range of 2-12 micrometers.
The thermal image can be achieved by means of a system with a heat source than can be made to rotate and produce a flash of heat at every rotation relative to a point of view with the speed of rotation determining the flash repetition rate. However, this type of system has the disadvantage of being omni-directional and inefficient. The image can also be confused by other nearby heat sources producing a pulsating heat image output.
A thermal image, as produced by a heat source, cannot be made to switch on and off rapidly. There is always a time lag created by heating and cooling cycles. In addition, ambient temperature has an effect. It is difficult to control power input to prevent an additional visual input.